As far as we can tell... Yes, such a magnet exists. But it costs the power of a small city to maintain its field, and the patient would experience all kinds of strange effects, including levitating in it as it induced magnetic forces across their water molecules...

(Seriously though, there are research magnets powerful enough to levitate plastic that people have jammed their hands into with no ill effects. It seems that across a wide range of intensities at least, the human body just does not care. This is, perhaps, surprising given how much electrochemical activity is necessary for continued homeostasis, but it appears to be observationally true).